Note the usual underscore after try and catch, and the extra parentheses
required after the catch.

Example: The following code calls the (lazy) function f
for each element, and prints messages about different exception types it
catches.

try_[f(arg1)].catch_<runtime_error>()[cout<<val("caught runtime error or derived\n")].catch_<exception>()[cout<<val("caught exception or derived\n")].catch_all[cout<<val("caught some other type of exception\n")]